CN112705131B - A kind of preparation method of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules - Google Patents

Abstract

The invention discloses a method for preparing deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules. In the present invention, hydroxypropyl-β-cyclodextrin and menthol are used as hydrogen bond donors for preparing DES, and cetyltrimethylammonium chloride is used as hydrogen bond acceptors. In a certain ratio of hydrogen bond donors and hydrogen Under the bond acceptor and temperature, a liquid homogeneous phase is formed, and β-cyclodextrin can interact with non-covalent host-guest to wrap menthol hydrophobic small molecules in the hydrophobic cavity of the macrocyclic sugar, and menthol can interact with hydroxypropyl The base-β-cyclodextrin forms a stable clathrate, improves the stability of menthol, and can be used in the production of flavored cigarette paper because it can be miscible with ethanol in any proportion. The microcapsules prepared by this method make full use of the synergistic effect of DES and β‑CD, and have the characteristics of slow release, stability and high embedding rate. The preparation method is simple, and the wall material is environmentally friendly and safe. The microcapsules are applied in flavored cigarette paper , the aroma can be released stably, evenly and continuously, and has a good slow-release effect.

Description

A kind of preparation method of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules

technical field

The invention belongs to the technical field of slow-release essence preparation, and in particular relates to a method for preparing deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules.

Background technique

Menthol is widely used in food and tobacco industries because of its cooling activity. In view of the fact that menthol is very easy to sublimate or volatilize, it not only produces strong stimulation in the production process, but also affects the life of the product. Only by effectively protecting the stability of menthol can the mint products with better quality be produced. Various methods can be used to protect the stability of menthol. Using β-cyclodextrin (β-CD) as the main body to include menthol guests to form a stable inclusion compound is one of the effective methods to protect menthol, but the low water solubility of β-CD affects the inclusion of menthol. The inclusion rate can be improved by modifying β-CD and changing the inclusion system.

A low eutectic reagent (DES) is a mixture of two or more hydrogen bond donors (HBA) and hydrogen bond acceptor compounds (HBD), typically a specific molar ratio of quaternary ammonium salt (choline chloride) and The hydrogen bond donors (urea, glycerol, sugar or carboxylic acid) mixed in a certain molar ratio interpenetrate at the melting point to form a liquid mixture at room temperature. Since DES contains large asymmetric ions with low lattice energy, charge delocalization through, for example, hydrogen bonding between halide ions and hydrogen donor moieties causes the melting point of the mixture to be much lower than that of the individual components, while being environmentally friendly, It is easy to degrade, easy to prepare, and the components are relatively cheap. DES is currently mainly used in the fields of metal processing, synthetic media, adsorbed gases, dissolved drugs, stabilized natural pigments, purified crude oil, biodiesel, and extraction and separation. The application in the field of microcapsule preparation has not been reported. Due to its good compatibility with essence and low melting point, it has great application prospects in the field of microcapsule preparation.

The present invention uses hydroxypropyl-β-cyclodextrin (β-CD) and menthol as hydrogen bond donors for preparing DES, and cetyltrimethylammonium chloride as hydrogen bond acceptors. The bond donor and the hydrogen bond acceptor and temperature form a liquid homogeneous phase. Using β-cyclodextrin, it can wrap menthol hydrophobic small molecules in the hydrophobic cavity of the macrocyclic sugar (host) through non-covalent host-guest interaction. Molecule (guest), menthol can form stable clathrate with hydroxypropyl-β-cyclodextrin, improve the characteristics of menthol stability, because it can be miscible with ethanol in any proportion, it can be used in the production of flavored cigarette paper. The microcapsules prepared by this method make full use of the synergistic effect of DES and β-CD, and have the characteristics of slow release, stability and high embedding rate. The preparation method is simple, and the wall material is environmentally friendly and safe. The microcapsules are used in flavored cigarette paper , the aroma can be released stably, evenly and continuously, and has a good slow-release effect.

Contents of the invention

The object of the present invention is to provide a method for preparing deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules in view of the deficiencies in the prior art.

The purpose of the present invention is achieved through the following technical solutions.

A method for preparing deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules, comprising the following steps: cetyltrimethylammonium chloride and menthol in a molar ratio of 1: 1 Mix, heat to 70-80°C, stir to dissolve, cool to room temperature, add hydroxypropyl-β-cyclodextrin ethanol solution, and stir for 30-60min to obtain a transparent liquid deep eutectic solvent/hydroxypropyl-β- Cyclodextrin Menthol Microcapsules

The concentration of the hydroxypropyl-beta-cyclodextrin ethanol solution is 40%-70%.

The mass ratio of the hydroxypropyl-β-cyclodextrin ethanol solution to menthol is 6-10:1.

The prepared deep eutectic solvent/hydroxypropyl-beta-cyclodextrin menthol microcapsules can be miscible with ethanol in any proportion, and the ethanol concentration is 90%-100%.

Apply the prepared deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules to cigarette paper, specifically by spraying the surface of the deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules Ethanol solution and drying, the weight ratio of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules to cigarette paper is 0.5-1:100.

Compared with the prior art, the present invention has the following significant advantages:

1. Utilizing β-cyclodextrin and menthol as hydrogen bond donors for the preparation of DES, and cetyltrimethylammonium chloride as hydrogen bond acceptors to prepare deep eutectic solvents, at a certain temperature, low The eutectic solvent is a homogeneous liquid phase, and by stirring, the menthol can fully enter the inner cavity of the β-cyclodextrin to form a stable host-guest inclusion compound and obtain a microcapsule product.

2. The microcapsules prepared by the method make full use of the deep eutectic solvent to act as a solvent, and simultaneously menthol is a guest molecule, and the menthol embedding rate is greatly improved. Simultaneously, the preparation method is simple, the required time is short, and the microcapsules The product is stable and miscible with ethanol in any proportion, laying the foundation for subsequent applications.

3. The raw materials used are utilized to the maximum extent, and at the same time, the raw materials are environmentally friendly and safe, and will not cause negative effects on subsequent applications.

4. When the microcapsule is applied to cigarette paper, the aroma can be released stably, uniformly and continuously, and has a good slow-release effect.

Detailed ways

The present invention will be further described below in conjunction with the examples, but the protection scope of the present invention is not limited thereto.

Example 1:

1. Preparation of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules:

(1) Preparation of ethanol solution of hydroxypropyl-β-cyclodextrin: dissolve 3000g of hydroxypropyl-β-cyclodextrin in 7000g of absolute ethanol, stir to dissolve, and mix well;

(2) Mix 320g of cetyltrimethylammonium chloride with 234g of L-menthol, heat to 70°C, stir to dissolve, cool to room temperature, and add 1410g of hydroxypropyl-β-cyclone prepared in step (1) Dextrin ethanol solution was stirred for 30 minutes to obtain transparent liquid deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules.

2. In the cigarette paper manufacturing process, the spraying device is introduced before the cigarette paper is cut, and the prepared hydroxypropyl-β-cyclodextrin menthol microcapsule ethanol solution is evenly sprayed on the on the cigarette paper and dried in a drying cylinder to obtain a menthol cigarette paper.

3. Sensory evaluation of sample cigarettes

After the rolled cigarette samples were balanced for 48 hours under the conditions of humidity 60±5°C and temperature 22±2°C, professional cigarette sensory evaluation personnel conducted sensory evaluation according to GB5606.4-2005. The evaluation results are shown in Table 1.

Example 2:

1. Preparation of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules:

(1) Preparation of hydroxypropyl-β-cyclodextrin ethanol solution: dissolve 3500g hydroxypropyl-β-cyclodextrin in 6500g 95% ethanol, stir to dissolve, and mix well;

(2) Mix 320g of cetyltrimethylammonium chloride with 234g of L-menthol, heat to 75°C, stir to dissolve, cool to room temperature, and add 1870g of hydroxypropyl-β-cyclone prepared in step (1) Dextrin ethanol solution was stirred for 40 minutes to obtain transparent liquid deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules.

2. In the cigarette paper manufacturing process, the spraying device is introduced before the cigarette paper is cut, and the prepared hydroxypropyl-β-cyclodextrin menthol microcapsule ethanol solution is evenly sprayed on the on the cigarette paper and dried in a drying cylinder to obtain a menthol cigarette paper.

3. Sensory evaluation of sample cigarettes

With embodiment 1, the result of evaluation and absorption is shown in Table 1.

Example 3:

1. Preparation of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules:

(1) Preparation of hydroxypropyl-β-cyclodextrin ethanol solution: dissolve 4000g hydroxypropyl-β-cyclodextrin in 6000g 90% ethanol, stir to dissolve, and mix well;

(2) Mix 320g of cetyltrimethylammonium chloride with 234g of L-menthol, heat to 80°C, stir to dissolve, cool to room temperature, add 2300g of hydroxypropyl-β-cyclone prepared in step (1) Dextrin ethanol solution, stirred for 50min, cooled to room temperature to obtain transparent liquid deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules.

2. In the cigarette paper manufacturing process, the spraying device is introduced before the cigarette paper is cut, and the prepared hydroxypropyl-β-cyclodextrin menthol microcapsule ethanol solution is evenly sprayed on the on the cigarette paper and dried in a drying cylinder to obtain a menthol cigarette paper.

3. Sensory evaluation of sample cigarettes

With embodiment 1, the result of evaluation and absorption is shown in Table 1.

Example 4:

1. Preparation of deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules:

(1) Preparation of hydroxypropyl-β-cyclodextrin ethanol solution: dissolve 3500g of hydroxypropyl-β-cyclodextrin in 6500g of absolute ethanol, stir to dissolve, and mix well;

(2) Mix 320g of cetyltrimethylammonium chloride with 234g of L-menthol, heat to 80°C, stir to dissolve, cool to room temperature, and add 1600g of hydroxypropyl-β-cyclone prepared in step (1) Dextrin ethanol solution was stirred for 60 minutes to obtain transparent liquid deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules.

2. In the cigarette paper manufacturing process, the spraying device is introduced before the cigarette paper is cut, and the prepared hydroxypropyl-β-cyclodextrin menthol microcapsule ethanol solution is evenly sprayed on the on the cigarette paper and dried in a drying cylinder to obtain a menthol cigarette paper.

3. Sensory evaluation of sample cigarettes

With embodiment 1, the result of evaluation and absorption is shown in Table 1.

Table 1 Smoking results of cigarette samples

Table 2 Smoking results of cigarette samples after storage of menthol cigarette paper for 6 months

Evaluation project total score Example 1 Example 2 Example 3 Example 4 luster 5 5 5 5 5 aroma 32 28.22 29.08 28.41 29.20 Harmonize 6 5.35 5.52 5.36 5.45 Miscellaneous 12 10.86 10.56 10.91 11.00 irritant 20 18.02 18.70 18.24 18.90 aftertaste 25 21.21 21.30 21.28 21.35 total 100 88.66 90.16 89.2 90.9

The results in Table 1 show that from the point of view of smoking effect, the deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules prepared by the present invention are used in cigarette paper, and a better effect is obtained.

The results in Table 2 show that after 6 months of storage, the cigarettes made of mint-type cigarette paper are evaluated and smoked. The results show that the mint-type cigarette paper has a longer storage time, the mint flavor is basically not emitted, and the smoking can still be maintained. The taste is consistent and can be applied to the production of normal menthol cigarettes.

Claims (2)

1. a preparation method of deep eutectic solvent/hydroxypropyl-beta-cyclodextrin menthol microcapsules, is characterized in that, comprises the following steps: cetyl trimethyl ammonium chloride and menthol in molar ratio Mix 1:1, heat to 70-80°C, stir to dissolve, cool to room temperature, add hydroxypropyl-β-cyclodextrin ethanol solution, stir for 30-60min to obtain transparent liquid deep eutectic solvent/hydroxypropyl- β-cyclodextrin menthol microcapsules; The concentration of the hydroxypropyl-β-cyclodextrin ethanol solution is 40%-70%; The mass ratio of the hydroxypropyl-β-cyclodextrin ethanol solution to menthol is 6-10:1. 2. use the application of deep eutectic solvent/hydroxypropyl-beta-cyclodextrin menthol microcapsules prepared according to the method of claim 1 in cigarette paper, it is characterized in that, described deep eutectic solvent is used in described application Solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules are sprayed on the surface of cigarette paper and dried, and the weight ratio of the deep eutectic solvent/hydroxypropyl-β-cyclodextrin menthol microcapsules to cigarette paper is 0.5 -1:100.